The present invention relates to a liquid crystal drive network for converting segment signals having a high frequency and derived from a general-purpose LSI (large-scale integrated circuit) computation circuit to a form suited for liquid crystal display units.
An LSI computation circuit generally provides segment display signals for plural digits in a time division fashion in order to reduce the necessary number of the output terminals of the LSI computation circuit when multi-digit numeral information is desired to be displayed in an electronic apparatus such as an electronic calculator. A general-purpose LSI computation circuit provides segment display signals at a high division frequency, since the conventional display units such as discharge type character indication tubes and phosphorescence type tubes can respond to signals having a relatively high frequency. It is necessary to provide a pulse frequency and pulse width converter including signal storage elements when the segment display signals from the general-purpose LSI computation circuit are desired to be used for activating liquid crystal display units, since the liquid crystal display units can not respond to the signals having a high frequency.
The conventional converter mainly comprises segment signal input terminals, storage elements and segment signal output terminals, the respective number of which corresponds to the number of the segment signal output terminals of the LSI computation circuit. It is required that the necessary number of terminals of the converter be reduced in order that integrated circuit technology can be applied to fabricate the converter.